MI5 was still investigating a vulnerable teenage girl until her death even after terrorism charges were dropped, an inquest ...

Guy Burgess's passport and briefcase left behind when he fled to Moscow in 1951 A battered leather briefcase left behind by Guy Burgess when he fled to Moscow in 1951 is among 20 objects from MI5 ...

MI5 only began releasing records to the U.K.’s public archives in 1997, generally 50 years after the events have passed. Even now, it controls what to release and what to keep secret.